A 3I spinning disk confocal microscope is requested for sensitive fluorescence imaging of living cells. The microscope will serve 8 major users and a number of minor users from multiple departments throughout Vanderbilt University Medical School and College of Arts &Sciences. The users require confocal fluorescence imaging of dynamic processes in living cells in an instrument that provides maximum sensitivity and spatial resolution, minimal photobleaching and phototoxicity, and ease of use. They also wish to perform photobleaching, photactivation and photoablation of live specimens. Our 8 major users are all experienced in confocal microscopy and provide documentation showing that the new CSU22 spinning Nipkow disk technology provides improvements for live cell imaging that are vastly beyond those afforded by other conventional confocal microscopes at Vanderbilt University. The improvements provided by the 3I system include: continuous monitoring of live cells in time-lapse with minimal bleaching or damage;detection of faint and minute details not visible in conventional instruments;laser options for CFP/GFP/YFP/RFP imaging;intensifier-camera package for dynamic tracking of faint signals, Mosaic unit for simultaneous FRAP or photoactivation, and Micropoint system for pulsed dye cell laser bleaching, ablation and cutting. The 3I microscope will be installed in a centralized microscope room where it will be supervised and maintained. The application is supported by a broad base of interest, need, and financial support by the university and will serve a large NIH-funded scientific community. PUBLIC HEALTH RELEVANCE: A spinning disk confocal microscope will allow us to image various processes in living cells. We are particularly interested in using this instrument to gain a better understanding of cell migration, which is fundamental to many biological processes, including embryogenesis, wound healing, and the inflammatory response, as well as pathological processes, such as cancer, atherosclerosis, arthritis and congenital developmental brain defects. A better understanding of these processes could lead to new therapeutic approaches for these disorders.